Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Grok Code Fast 1
39
Mellum2-12B-A2.5B-Thinking
59
Pick Mellum2-12B-A2.5B-Thinking if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if coding is the priority or you need the larger 256K context window.
Coding
+0.9 difference
Grok Code Fast 1
Mellum2-12B-A2.5B-Thinking
$0.2 / $1.5
N/A
172 t/s
N/A
2.81s
N/A
256K
128K
Pick Mellum2-12B-A2.5B-Thinking if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if coding is the priority or you need the larger 256K context window.
Mellum2-12B-A2.5B-Thinking is clearly ahead on the provisional aggregate, 59 to 39. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Mellum2-12B-A2.5B-Thinking is the reasoning model in the pair, while Grok Code Fast 1 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Grok Code Fast 1 gives you the larger context window at 256K, compared with 128K for Mellum2-12B-A2.5B-Thinking.
Mellum2-12B-A2.5B-Thinking is ahead on BenchLM's provisional leaderboard, 59 to 39.
Grok Code Fast 1 has the edge for coding in this comparison, averaging 70.8 versus 69.9. Mellum2-12B-A2.5B-Thinking stays close enough that the answer can still flip depending on your workload.
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